Our REC league has a 5 run per inning rule till the last inning.
When we played rec, we had the same rule. I personally don't like it.
Yep, I want to run up the score on 8-12 yo kids! Seriously, I have no problem with 5 runs per half inning, but I do think it needs to be that way for ALL innings for these two reasons:
1) An open last inning still allows for a large blowout score which is one of the things a 5 run rule is designed to protect against.
2) You limit the scoring in progress by a team per inning. If they have a bad last inning where the wheels come off they could lose the game when they never would have in a
non modified situation.